A variety of membranes have been developed over the years for application as solid polymer electrolytes for fuel cells and other electrochemical applications. These polymers have typically been perfluorinated aliphatic compositions, such as those described in U.S. Pat. Nos. 3,282,875 and 4,330,654. These compositions are very expensive membranes, and in the case of the '875 patent tend to exhibit poor fuel cell performance characteristic at high current densities. Alternatively, a series of low-cost polyaromatic-based systems have been investigated, such as those described in U.S. Pat. Nos. 3,528,858 and 3,226,361. These materials suffer from poor chemical resistance and mechanical properties which tend to limit their use in fuel cell applications. The investigation of other materials has involved the study of polymers containing the monomer unit .alpha.,.beta.,.beta.-trifluorostyrene, for example, those described in U.S. Pat. No. 3,341,366 and Japanese Unexamined Patent Publication (Kokai) No. 53-26884. However, these compositions suffered from poor mechanical properties in the case of the '366 patent, and very low polymer yield in the case of the Japanese patent publication.
It is therefore an object of the invention to produce, in high yield, a low-cost ion-exchange polymer membrane with favorable chemical and mechanical properties.
It is also an object of the invention to produce an ion-exchange polymer membrane that is suitable for use in a wide variety of applications, including electrochemical applications such as fuel cells.